Dental instrument



W. W. BOLLS.

DENTAL INSTRUMENT. APPLICATION FILED FEB. I8, 1920.

1,356,755. Patented Oct. 26,1920.

2 SHEETSSHEET l.

Ch rm/nu; v

W. W. BOLLS- DENTAL INSTRUMENT. APPLTCATION FILED FEB. I8, 1920.

Patented 001:. 26, 1920.

2 SHEETS-SHEET 2 WILLIAM W. 'B'oLLs, OFWASHINGTON, DISTRICT on COLUMBIA). f j

DENTAI ms'rzaiuiunn'rf r Application filed February 18, 1920. Serial No.- 359,634:

T 0 (all to 710m it may concern Be it known that 1, WILLIAM W. Bo'LLs, a citizen of the United States, residing at l/Vashington, in the District of Columbia,

have invented certain new and useful Improvements in Dental Instruments, of wh ch the following ,is 'a specification.

This invention relates to certain new and usei'ul improvements in dental lnstruments,

and pertains more particularly to improvementupon Letters Patent issued to me May 27-, 1913, No.1063109. k

The primary object of the invention is to provide an insti-umentwhe'rein the brjoach is held and rotated at an angle without bodily bending orfiemng of the broach, so that the latter regardless of 1ts angular relation to the handle is at all times maintained straight L throughout its entire length:

Afurther object of he invention is I to provide an instrument which will allow 'all types of breaches, etc, to be used irrespec ti've of whether same are or "not capable of being fle: ed,'ancl' toalso "effect TOY/M31011 of the broach in a definite and selective plane witl'iont any wabbling or eccentric movement,

Sill further the invention aims to provide Y an instrument off the type, mentioned which can be held and rotated with ail-under grip of the hand i. 6., with the hand beneath the device so that the latter can be held ..'in a manner similar to holding of'a pen or pencil in writing and 'posltlvely' rotated when so held.

In the drawings Figure 1, is a side elevation, showing a few positions of the breach 1n dotted lines; 7

Fig.2, is a section on line 2-2offFig.

Fig. 3" is a" detail perspective view of the chuck and a broach shank formed for reception therein: V

Fig. 4 is a detail fragmentary perspective view of the arm and its eye which engages and holds the broach at the desired angle:

Fig. 5 is a side elevation of a modified form of the invention, depicting an undergrip type of instrument:

Fig.6, is a side elevation of Fig. 5, at right angles thereto: v

Fig. 7 is an enlarged sectional view on line 77 of Fig. 6, and

Fig. 8, is an enlarged sectional view on line 8- 8 of Fig. 6. I

In proceeding in accordance with the present invention, a handle 1, is employed formed with a socket l2 which the stem 3 of the broach holder proper is rotata'blyreceived. A knurled ribbed, or roughened head 1 is secured to the stem so as to be eitfectlvely gripped by the fingers and rotated.

Specification of Letters Patent, Patgntefl fl'cij ,1 29. a I

A relativ'ely short. coil spring 5, is secured at one end to the outer end of shank 3v and r at its opposite end hasa chuck '6 afiixed thereto. The] chuck has a bore 7 in which the shank of the breach is received and held by a pivoted "L -shaped latch B ier-med with a substantially U-shaped notche which engage about the oppositely notched parts 10 of thefbroach so as tothereby hold the latter securely within the chuck. l i

Theann' ii is equip ed with split spring collar 12 which frictio'nally grips the shank 13 of the handle 1,and'has an open eyel l receiving the broach;

In the modified fol-m of the f 'ihve'ntion which is particularly designed for use dentists ;who prefer to hold the 'broachsimi lar to the holding of a pen'or pencil in writing handle 20,'h'as a pair of depressible spring arms 21 secured at one end thereto and on opposite sides of the handle. The

outeror free en'dsof the 'a-rms have rack bars 22 secured thereto, for example by heading as depicted 'at'28. The teeth of the rack mesh with theft'eeth of a pinionf2t, the

racks being disposed on opposite sides of the i I pinion. The pinion 24 is carried by-the stem 25 of the breach holder proper, "inward movement "of ithe'stem being restricted by. a

stop", such as pin 26, suitably secured within the handle 20. in order to allowthe racks to pass the opposi'tespring arm 21, upon de f pression of such arms the latter are provided with cutaway parts 27,.and forthepu'rpose latter, con s ringsea'may 'be'pla'ced menof assuring restoration to normal position off the spring arms followlng depression of the.

circling relation about the racks as depicted in Fig. 6.

The coil spring 29, chuck 30 and the arm 7 31, are all similar to the corresponding parts in the preferred form of the'invention, ex-

cepting that the arm 31, is shorter.

In both forms of the invention it will be understood that the arms 11 or 31 can be the chuck carrying the broach'and the stem enables the dentist to ascertain by the sense bent by thefingers to various positions and of the feel, the eflectivenessof the broach tool or instrument.

What is claimed-is 1. In combination with a handle, a stem rotatably borne by the handle, a broach holding chuck, means carried by the handle and; formed to directly engage the broach between the ends of the broach to hold the latter at an angle to the handle, and a" flexible connection between the stem and chuck.

2. Incombination with a handle, a stem rotatably borne by the handle, a broach hold ing chuck, means carried by the handle and formed to directly engage the broach between the ends'of the broach to hold the latter at an angle to the handle, and a coil spring. secured at one end to the chuck and at its opposite en'd'to the stem.

3. In, combination .with a handle and means borne thereby to hold a broachat an" angle thereto by direct engagement with the broach between its ends, broach holding means, means borne by the handle to rotate the broach-holding means, and means to con-,

nect the broach holding means to said rotatingmeans whereby to allow the broach to be disposed at Varying angles to the handle while maintaining the broach straight. I

4. In combination with a'handle,'a stem rotatably borne thereby, a pinion connected to the stem, broach holding means connected to the stem, a pair of depressible spring arms connected at one end to the handle, and racks carried by the opposite ends of the arms and meshed with opposite sides of the V pinion.

5. In combination with a handle, a stem rotatably borne thereby, a pinion connected to the stem, broach holding means connected to the stem, a pair of depressible spring arms connected at one end to the handle,

racks carried by the opposite ends of the arms and meshed with opposite sides of the pinion, and coil springs encircling the racks and interposed between the handle and arms for moving the latter to normal outward position.

6. In combination with a handle, a stem rotatably borne thereby, broach holding 0 means connected to the stem, and depressible means to rotate the stem by and upon depression thereof.

7. In combination with a handle, a steml rotatably borne thereby, broach-holding means connected to the stem, a depressible spring arm carried by the handle, and means operated by the arm to rotate the stem by; and upon depression of said spring arm. 8. In combination with a holder, means .ently of the holder, means between the robroach' may be rotated while disposed at Varying angles to the handle and while maintaining same bodily straight and' means to directly engage the broach between its ends to hold' 'same in angular. relation to the handle. 1

9; In combination with a handle, a stem rotatably borne thereby, broach holding means connected to the stem, an arm borne by the handle andformed. to engage the broach between its ends, a flexible connection 7 between the stem and holding means, depressible finger operated means borne by the handle to rotate the stem,and means operated by said depressible meansto engage and rotate the stem 'by and upondepression of I said depressible means. V .10. In combination with a handle, a stem rotatably borne thereby, broach holding means connected to the stem, reciprocable means carried by the handle and movable toward and away therefrom, and means actuated by said reciprocable means to engage and rotate the stem. In testimony whereof I aflix my signature.

WILLIAM.W. BoLLs.

to support and rotate abroach independtation means and the broach whereby the 

